Field of the Invention
This invention relates generally to liquid crystal displays, and more particularly to forming alignment layers on liquid crystal displays.
Description of the Background Art
Liquid crystal (LC) displays are known. LC displays (LCDs) utilize optically active materials that affect the polarization of light passing therethrough based on their alignment and the electric field to which they are exposed. This attribute of LCs is utilized for modulating light on a pixel-by-pixel basis in a display. In order to properly align liquid crystals, manufacturers of LC displays apply a polymer layer (e.g. a polyimide layer) on both sides of the LC layer. The polymer layer is then rubbed in a pre-designed direction, causing surface effects that align the LC molecules along the rubbing direction.
Rubbing is not capable of generating nanometer scale uniform alignment features on surface. For applications of LCs on silicon substrates (i.e. LCOS), the polyimide layer must be thin, and so the rubbing force must be relatively low so as not to damage polyimide layer. As a result, the LC alignment in LCOS devices is not as complete as it could be in LCDs.